Atomizer



June 20, 1944. P, D. NIELSEN ATOMIZER Filed July 5 1940 Patented June20, 1944 ATOMIZEB Peer I). Nielsen, Lorain, Ohio, assignor to NationalTube Company, a corporation of New Jersey Application July 3, 1940,Serial N0. 348,887 2 Claims. (Cl. 299-118) This invention relates toatomizers and is particularly concerned with the problem of thoroughlyatomizing liquid fuels such as heavy oil or tar, whereby to conditionsuch fuels for burning in industrial furnaces.

A specific example of the invention is illustrated by the accompanyingdrawing, in which:

Figure 1 is a top view;

Figure 2 is a section from the line 11-11 in Figure 1; and

Figures 3 and 4 are cross sections from the lines III-III and IV-IV,respectively, in Figure 1.

More specifically, the atomizer illustrated by these drawings comprisesa body I providing a chamber having an inside 2 of cylindrical contourterminating with a Venturi throat 3, the chamber having an entrance 4 atthe end of the inside 2 opposite the throat 3 and which pointstangentially respecting the cylindrical inside. This entrance 4 connectswith a pipe 5 carrying an atomizing fluid under pressure, this fluidejecting at the entrance 4 and swirling forwardly along the inside 2,its velocity being greatly increased at the throat 3 while its pressureis decreased. The fluid leaves the chamber by way of an outlet 8, itgoing to a suitable burner.

A liquid fuel supply tube I extends longitudinally of the abovedescribed chamber concentrically respecting its cylindrical inside 2,the tube being cylindrical throughout its length inside the chamber andpassing through the end of the chamber by way'of a stufllng box 8 whichpermits the tube to slide longitudinally without leakage of theatomizing fluid, the tube being in threaded engagement with a nut 8turned by a handwheel ill and rotatively fixed against longitudinalmovement by a bracket ii fixed to the body I. With this arrangement, theinside end of the tube 1 can be adjustably positioned respecting thethroat 3, this being done by turning the handwheel Ill.

The end of th tube 1 has a flaring opening i2, and a flaring head l3cooperates with this opening to form a flaring annular orifice. Thisannular orifice is adjustable by reason of the flaring head l8 beingpositioned through the medium of a rod 14 passing longitudinally throughthe tube 1, the rod I 4 being itself positioned by being inscrew-threaded engagement with a nut I! mounted by a pipe fitting T Itscrewed onto the end of the tube 1. The nut I5 is screwed into thefitting sufllciently tightly to be nonrotative, the rod I 4 having asquared end [4 to which a wrench may be applied and a stuillng box I!serving to seal the rod against leakage. The fuelis introduced by way ofa pipe i 8 screwed into the fitting ii, the fuel traveling along throughthe tube and ejecting as a flaring annular film through the orificebetween th hole I! and the head I I, this film ejecting concentricallyinto the swirling atomizing fluid at the throat 3 where the atomizingfluid is at high velocity and low pressure.

The method of using the atomizer consists in heating the liquidiuel'introduced to the atomizer through the pipe ll, to a temperaturethat is sufflciently high to cause the fuel to vaporize at atmosphericpressure. The fuel is maintained liquid by applying a suitable pressureto it, and it therefore ejects as a flaring annular liquid film into thethroat 3. Here the atomizing fluid, which may be steam or air, is movingat its highest velocity but is at a relatively low pressure, the resultbeing that the annular liquid film is mechanically atomized with greatviolence by the rapidly whirling atomizing fluid and, at the same time,vaporized due to the pressure reduction of the atomizing fluid caused bythe increase in its velocity resulting from its constriction by theVenturi throat 3. The result is a very complete atomization of theliquid fuel, this greatly increasing its heating efllciency when it isburnt by a burner of proper design. a

Different types of fuels may be accommodated by working the handwheel I!to adjust the point where the flaring annular fllm of liquid fuel isejected respecting the throat I, to the end of producing the bestresults. The proper position is best determined experimentally,observation of the flame produced being the best guide. Furthermore, thethickness of the flaring annular film of fuel may be varied by turningthe rod l4, this being another adjustment that can be most exactly madeby observation of the results produced. Since the liquid fuels sometimestend to clog orifices, it may happen that the annular orifice providedby the hole [2 and head I! becomes clogged, but this is easily remediedby turning the rod l 4 so as to move the head l3 forward, this openingthe orifice so as to permit it to clear.

I claim:

1. An atomizer for liquid fuel, including a chamber having a cylindricalinside contour terminating with a Venturi throat and provided with atangential inlet spaced from said throat with means for supplying saidinlet with atomizing fluid under pressure, and a cylindrical liquid fuelsupply tube extending longitudinally of said chamber concentricallytherewith with a flaring annular orifice adjacent said throat andpointing theretowards, said orifice being positioned to elect a flaringannular fllm of liquid fuel into said throat at a position where thevelocity of the whirling atomizing fluid passing theretlircugh isrelatively high.

2. A method of atomizing liquid fuel, comprising creating a whirlingflow of atomizing fluid under pressure, constricting said flow-toProduce a 5 high-velocity, low-pressure zone of whirling fluid, heatingthe liquid fuel to above its atmospheric

